Actor Johnny Depp was forced to overcome his fear of singing in public for new musical Sweeney Todd.

The 44-year-old feared he would have to back out of the film, warning director Tim Burton that he wasn't very confident in his singing abilities.

He says, "I think I was probably more frightened than anyone. I've never tried karaoke. It scares the hell out of me. I've never been that drunk - and I've been drunk. Tim said he didn't know if I could sing, and likewise, I didn't know if I could sing.

"I did these demos in my friend's garage studio because I didn't know if I'd be able to hit a note, to be honest, I really didn't. I did that and sent it to Tim and he said we're going to be okay. And then I became a bit more confident."